In the above-described electric vehicle, pitching vibration which moves up and down in the longitudinal direction of a vehicle body not only gives discomfort to an operator but also affects control of the vehicle body. In particular, a forklift truck for carrying cargo undergoes a change in the position of the center of gravity of the vehicle in its entirety on placing the cargo and easily causes pitching vibration. Thereby, the operator feels discomfort or the cargo collapses to result in lower workability.
For example, Patent Document 1 shown below discloses a vehicle-body control device for an electric vehicle which takes pitching vibration into account. That is, the vehicle-body control device is provided with an accelerator input processing unit which issues a speed command (motor rotation number command) depending on a depression amount of an accelerator of the electric vehicle, a pitching detection unit which detects generation of pitching vibration on the basis of detected speed which is an actual rotational speed of a motor, and a speed command adjusting unit which outputs externally the speed command issued by the accelerator input processing unit when the pitching detection unit does not detect pitching vibration but searches for a speed command which is half the value of a sum of a maximum detected speed and a minimum detected speed at the time of development of pitching vibration and outputs the speed command externally, in place of the speed command issued by the accelerator input processing unit, when the pitching detection unit detects pitching vibration.
Patent Document 1: Japanese Patent No. 3935039